High accuracy optical elements are applied in various fields. For example, ultraprecise aspherical mirrors are necessary for
developing third-generation synchrotron radiation and XFEL (X-ray Free Electron LASER) sources. In order to make such high
accuracy optical elements, it is necessary to realize the measurement of aspherical mirrors with high accuracy. But there has been
no measurement method which simultaneously achieves these demands yet. So, we develop the nanoprofiler that can directly
measure the any surfaces figures with high accuracy. The nanoprofiler gets the normal vector and the coordinate of a
measurement point with using LASER and the QPD (Quadrant Photo Diode) as a detector. And, from the normal vectors and
their coordinates, the three-dimensional figure is calculated. In order to measure the figure, the nanoprofiler controls its five motion axis numerically to make the reflected light enter to the QPD’s center. The control is based on the sample's design formula.
We measured a concave spherical mirror with a radius of curvature of 400 mm by the deflection method which calculates
the figure error from QPD’s output, and compared the results with those using a Fizeau interferometer. The profile was
consistent within the range of system error. The deflection method can’t neglect the error caused from the QPD’s spatial
irregularity of sensitivity. In order to improve it, we have contrived the zero method which moves the QPD by the
piezoelectric motion stage and calculates the figure error from the displacement.

The autocollimator and moveable pentaprism based DLTP [NIM A 616 (2010) 212-223], a low-budget, NOM-like
profiler at the Advanced Light Source (ALS), has been upgraded to provide fast, highly accurate surface slope metrology
for long, side-facing, x-ray optics. This instrument arrangement decreases sensitivity to environmental conditions and
removes the gravity effect on mirror shape. We provide design details of an affordable base tool, including clean-room
environmental arrangements in the new ALS X-ray Optics Laboratory with advanced temperature stabilization and
turbulence reduction, that yield measurements in under 8 hours with accuracy better than 30 nanoradians (rms) for super
polished,190 mm flat optics, limited mainly by residual temporal instability of the experimental set-up. The upgraded
DLTP has been calibrated for highly curved x-ray optics, allowing same day measurements of a 15 m ROC sphere with
accuracy of better than 100 nanoradians (rms). The developed calibration procedure is discussed in detail. We propose
this specific 15 m ROC sphere for use as a round-robin calibration test optic.

In beamlines at third-generation synchrotron radiation and X-ray free-electron-laser (XFEL) facilities, various mirrors
are used as deflection, focusing, and collimating optics. The required specifications for the mirrors depend on their
purpose. In recent years, high-precision aspheric mirrors and flat mirrors, with a figure error less than 10 nm are used as
diffraction-limited focusing optics and deflection optics, respectively. The origins of the figure error are fabrication error,
gravitational deformation, and clamping deformation. In the case of the bend mirror, figure error is also induced by the
bender mechanism. The fabrication error is measured by a long trace profiler (LTP) [1] or by relative-angle determinable
stitching interferometry (RADSI) [2] with special high frequency of 0.1–1/mm. Deformation caused by gravity,
clamping, and bending should be measured under actual operating conditions because these deformations depend on the
direction of the mirror surface and the direction of clamping and bending, respectively. In recent years, in-situ and atwavelength
metrology techniques such as the Hartmann sensor, pencil beam, grating base and the speckle-effect-based
technique, have been reported [3-6]. These methods are able to investigate the profile of the mirror under real conditions,
including the effects of thermal bump; however, these techniques require X-rays and a long optical length to the detector.
We attempted to upgrade the LTP at SPring-8 using autocollimators for the precise measurement of height profiles under
conditions of both upward and horizontal reflection geometries. A portable Fizeau interferometer was installed for onsite
measurement.

X-ray microscopic analysis as a fundamental tool in various scientific fields is supported by advancements in highprecision
x-ray optics. Off-axis ellipsoidal focusing mirror optics, which can produce two-dimensional focus with a
mirror and has characteristics of high reflectivity and achromaticity, is quite attractive for use in microscopic analysis.
However, technical problems in fabrication prevent a realization of off-axis ellipsoidal mirrors with nanometer accuracy
for nano-focusing of hard x-rays. The purpose of this study was to resolve a problem of surface processing technique for
fabrication of nanofocusing ellipsoidal mirrors in the hard x-ray region. We developed two types of ultra-high-precision
surface processing machines by advancing the Elastic Emission Machining method. One is a machine for improvement
of surface roughness with a rotary type working head, and the other is a machine for a computer-controlled figure
correction with a small-aperture nozzle type working head. Using the rotary type machine, we confirmed that surface
roughness of 4.32 nm root-mean-square (RMS) on an off-axis ellipsoidal mirror surface was improved to 0.14 nm
(RMS) within a spatial wavelength range of shorter than several hundred microns. Using the nozzle type machine, we
demonstrated a figure correction in a spatial wavelength of longer than 100 μm with nanometer height accuracy. Ultrahigh-
precision surface processing technologies with the capability of fabricating nano-focusing off-axis ellipsoidal
mirrors were established.

The third generation synchrotron radiation source like High Energy Photon Source (HEPS, Beijing) requires X-ray optics
surface with high accuracy. It is crucial to develop advanced optics surface metrology instrument. The Long Trace
Profiler (LTP) is an instrument which measures slope in the long dimension of an optical surface. In order to meet the
accuracy requirements for synchrotron optics, a number of researches have been carried out to improve the LTP during
the last decades. Many variations have been installed worldwide. As a part of the advanced research of HEPS, the
metrology laboratory at Beijing Synchrotron Radiation Facility (BSRF, Beijing) has been conducting work of building a
new LTP since 2012. The accuracy of the instrument is expected to be <0.1μrad rms for component up to 1m in length.
In this paper, we present some design consideration for nano-accuracy LTP. Two error sources, including the
deformation of the granite structure and imperfect optical surface, are studied. We report our optimized configuration of
the granite structure and the dependences of the measurement error on the surface error. The results are considered as an
important instruction for the proper choice of each component in the profiler. We expect to bring the profiler into
operation in 2015.

Within our technology center for production of highly efficient precision gratings a versatile 4-circle UHV-reflectometer
for synchrotron radiation based at-wavelength characterization has been fabricated. The main feature is the possibility to
incorporate real live-sized gratings. The samples are adjustable within six degrees of freedom by a novel UHV-tripod
system, and the reflectivity can be measured at all incidence angles for both s- and p-polarization geometry. The
reflectometer has been setup in a clean room hutch and it is coupled permanently to the optics beamline PM-1 for the UV
and XUV range with the polarization adjustable to either linear or elliptical. The setup will be open to users by the end of
2014.

Modern, third-generation synchrotron radiation sources provide coherent and extremely bright beams of X-ray radiation.
The successful exploitation of such beams depends to a significant extent on imperfections and misalignment of the
optics employed on the beamlines. This issue becomes even more critical with the increasing use of active optics, and the
desire to achieve diffraction-limited and coherence-preserving X-ray beams. In recent years, significant progress has
been made to improve optic testing and optimization techniques, especially those using X-rays for so-called atwavelength
metrology. These in-situ and at-wavelength metrology methods can be used not only to optimize the
performance of X-ray optics, but also to correct and minimize the collective distortions of upstream beamline optics,
including monochromators, and transmission windows. An overview of at-wavelength metrology techniques
implemented at Diamond Light Source is presented, including grating interferometry and X-ray near-field speckle based
techniques. Representative examples of the application of these techniques are also given, including in-situ and atwavelength
calibration and optimization of: active, piezo bimorph mirrors; Kirkpatrick-Baez (KB) mirrors; and
refractive optics such as compound refractive lenses.

It has been designed a new type of interferometer working in extreme ultraviolet (XUV) region and intended for direct
imprinting of densest possible (for given wavelength) interference pattern into a substrate.
The interferometer belongs to the wave-front division category: each of its two aspheric mirrors reflects approximately
one half of incoming laser beam and focuses it into a point image. Both focused beams have to intersect each other, and
in the intersection region an interference pattern is generated. The closer the intersection region is to the abovementioned
point images, the smaller the interference field is, but simultaneously the smaller the fringe-pitch is.
This paper describes interferometer design (inclusive fringe-pitch calculation, and inclusive design of multilayer
reflection coatings for the wavelength 46.9 nm (Ar8+ laser) – ensuring equal reflectivity at different reflection angles).
The interferometer design is supplemented not only by ray-tracing verification of straight shape of interference fringes in
ideal interferometer, but also by modelling of interference pattern of real interferometer with various misalignments as
well as with random deformation of mirrors. These data enable to define necessary production as well as alignment
tolerances.

Applications for Cylindrical and near-cylindrical surfaces are ever-increasing. However, fabrication of high quality
cylindrical surfaces is limited by the difficulty of accurate and affordable metrology. Absolute testing of such surfaces
represents a challenge to the optical testing community as cylindrical reference wavefronts are difficult to produce. In
this paper, preliminary results for a new method of absolute testing of cylindrical wavefronts are presented. The method
is based on the merging of the random ball test method with the fiber optic reference test. The random ball test assumes a
large number of interferograms of a good quality sphere with errors that are statistically distributed such that the average
of the errors goes to zero. The fiber optic reference test utilizes a specially processed optical fiber to provide a clean
high quality reference wave from an incident line focus from the cylindrical wave under test. By taking measurements at
different rotation and translations of the fiber, an analogous procedure can be employed to determine the quality of the
converging cylindrical wavefront with high accuracy. This paper presents and discusses the results of recent tests of this
method using a null optic formed by a COTS cylindrical lens and a free-form polished corrector element.

The requirements on the quality of ultra-precise X-ray optical components for application in the Synchrotron Radiation
(SR) community are increasing continually and strongly depend on the quality of the metrology devices available to
measure such optics. To meet the upcoming accuracy goal of 50 nrad rms for slope measuring profilers, a dedicated
project, SIB58 Angles, consisting of 16 worldwide partners and supported by the European Metrology Research
Programme (EMRP) was started in Sep 2013. The project covers investigations on autocollimators under extremely
challenging measuring conditions, ray-tracing models, 2D autocollimator calibration (for the first time worldwide),
determination of error sources in angle encoders providing traceability by ‘sub-division of 2π rad’ with nrad uncertainty,
angle generation by 'ratio of two lengths' in nrad level, and on the development of portable precise Small Angle
Generators (SAGs) for regular in-situ checks of autocollimators’ performance. Highlights from the project will be
reported in the paper and the community of metrology for X-Ray and EUV Optics will be informed about its progress
and the latest work in angle metrology.

Performance of state-of-the-art surface slope measuring profilers, such as the Advanced Light Source’s (ALS) long trace
profiler (LTP-II) and developmental LTP (DLTP) is limited by the instrument’s systematic error. The systematic error is
specific for a particular measurement arrangement and, in general, depends on both the measured surface slope value and
the position along a surface under test. Here we present an original method to characterize or measure the instrument’s
systematic error using a bendable X-ray mirror as a test surface. The idea of the method consists of extracting the
systematic error from multiple measurements performed at different mirror bendings. An optimal measurement strategy
for the optic, under different settings of the benders, and the method of accurate fitting of the measured slope variations
with characteristic functions are discussed. We describe the procedure of separation of the systematic error of an actual
profiler from surface slope variation inherent to the optic. The obtained systematic error, expressed as a function of the
angle of measurement, is useful as a calibration of the instrument arranged to measure an optic with a close curvature
and length. We show that accounting for the systematic error enables the optimal setting of bendable optics to the desired
ideal shape with accuracy limited only by the experimental noise. Application of the method in the everyday metrology
practice increases the accuracy of the measurements and allows measurements of highly curved optics with accuracy
similar to those achieved with flat optics. This work was supported by the U.S. Department of Energy under Contract
No. DE-AC02-05CH11231.

Autocollimator-based long trace profiler requires precise angular calibration to perform accurate measurements for xray
mirrors. A prototype of a precision two-dimensional tip-tilting stage system has been designed and tested for a new
autocollimator-based long trace profiler at the Advanced Photon Source (APS), Argonne National Laboratory (ANL).
This flexural stage system is designed to meet challenging mechanical and optical specifications for producing high
positioning resolution and stability for angular calibration for autocollimator-based long trace profiler. It could also be
used as a precision mirror manipulator for hard x-ray nano-focusing with Montel mirror optics.
The mechanical design of a precision two-dimensional tip-tilting stage system as well as preliminary test results of its
precision positioning performance are presented in this paper.

The X-Ray Optics Laboratory (XROL) at the Advanced Light Source (ALS), a unique optical metrology lab, has been
recently moved to a new, dedicated clean-room facility that provides improved environmental and instrumental
conditions vitally required for high accuracy metrology with state-of-the-art X-ray optics. Besides the ALS, the XROL
serves several DOE labs that lack dedicated on-site optical metrology capabilities, including the Linac Coherent Light
Source (LCLS) at SLAC and LBNL’s Center for X-Ray Optics (CXRO). The major role of XROL is to proactively
support the development and optimal beamline use of x-ray optics. The application of different instruments available in
the lab enables separate, often complementary, investigations and addresses of different potential sources of error
affecting beamline performance. At the beamline, all the perturbations combine to produce a cumulative effect on the
performance of the optic that makes it difficult to optimize the optic's operational performance. Ex situ metrology allows
us to address the majority of the problems before the installation of the optic at a beamline, and to provide feedback on
design and guidelines for the best usage of optics. We will review the ALS XROL mission, lab design and arrangement,
ex situ metrology capabilities and performance, as well as the future plans for instrumentation upgrades. The discussion
will be illustrated with the results of a broad spectrum of measurements of x-ray optics and optical systems performed at
the XROL.

The design for a new XUV-Optics Beamline is presented. The collimated plane grating monochromator (PGM-)
beamline at a bending magnet is setup at the BESSY-II synchrotron radiation facility within the framework of the
blazed-grating production facility. Coupled to a versatile four-circle (ten axes) UHV- reflectometer as a permanent end
station the whole setup is dedicated to at-wavelength characterization and calibration of the in-house produced precision
gratings and novel nano-optical devices as well as mirrors, multilayered systems etc. It is also open to external projects
employing reflectometry, spectroscopy or scattering techniques. According to its purpose, this beamline has specific
features, such as: very high spectral purity, provided by two independent high order suppression systems, an advanced
aperture system for suppression of stray light and scattered radiation, a broad energy range between 10 eV and 2000 eV,
small beam divergence and spot size on the sample. Thus this Optics Beamline will become a powerful metrology tool
for reflectivity measurements in s- or p-polarisation geometry with linearly or elliptically polarized light on real optics up
to 360 mm length and 4 kg weight.

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Journal of Applied Remote SensingJournal of Astronomical Telescopes Instruments and SystemsJournal of Biomedical OpticsJournal of Electronic ImagingJournal of Medical ImagingJournal of Micro/Nanolithography, MEMS, and MOEMSJournal of NanophotonicsJournal of Photonics for EnergyNeurophotonicsOptical EngineeringSPIE Reviews